1. Field of the Invention
The present invention is directed to a new and improved filtering circuit for a speaker, and also to a new and improved speaker system.
More particularly, the present invention is directed to a new and improved filtering network especially for a coaxial speaker system, and to such a new and improved coaxial speaker system, in which the filtering network, notably the inductance coil thereof, can be securely and successfully mounted coaxially upon a magnet of the coaxial speaker, with little or no disadvantage and with great improvement in audio reception and in structural balance of such a speaker system.
2. Description of the Prior Art
Audio speakers for delivering sound reception from a source such as a microphone, radio, tape deck, etc. have been known for quite some time, and it has been desirable to mount such speakers in any number of different fashions, e.g., upon the ceiling or a ceiling panel, on a wall, or on part of an automobile. For example, Design Patent Nos. 238,185; 242,151; 247,562; and 255,234 illustrate designs for ceiling-mounted speakers, while U.S. Pat. Nos. 4,072,829; 4,143,249; and 4,439,643 illustrate mounting attachments for loudspeakers. U.S. Pat. No. 4,484,658 illustrates a support assembly for a speaker upon a ceiling panel.
Recently, multiple speakers containing a larger speaker component and a smaller speaker component have come into particular use to enhance sound delivery. For example, such multiple speakers are disclosed in U.S. Pat. Nos. 4,837,839 and 4,672,675. U.S. Pat. No. 4,733,748 also discloses a mounting device for a car radio loudspeaker, as does U.S. Pat. No. 4,143,249. U.S. Pat. No. 2,070,977 also discloses a relatively primitive version of a sound reproducing speaker.
In particular, a coaxial speaker involves mounting a smaller speaker component within a larger speaker component along the same axis, which greatly enhances delivery of audio reception. Such a smaller speaker component is termed a "high frequency" speaker or tweeter, in that such a smaller component blocks out delivery of sound of a relatively lower frequency range, while the larger speaker component is termed a "low frequency" speaker or woofer, in that such larger component either blocks out only high frequencies or is designed to receive the entire frequency range of sound, including low, mid-range and high frequencies. Such coaxial speakers also encompass a triaxial speaker in which a midrange speaker and a tweeter are both mounted upon a woofer as disclosed, e.g., in U.S. Pat. Nos. 4,672,675 and 4,837,839.
Because of the nature of sound delivery, it has been necessary to provide such coaxial-type speakers with a filtering network such as RLC filtering circuitry (R=resistor, L=inductor, and C=capacitor), in order to properly filter the sound between the woofer and tweeter components, and also the midrange component in the case of the triaxial-type speaker, to avoid distortion as much as possible. In other words, if such speaker components are used without such appropriate RLC filter circuitry, then the sound delivery over a middle or overlapping range between the woofer and tweeter will be magnified or multiplied, resulting in distortion of sound and in undesirable noise and audio effect. Accordingly, such filter circuitry has been required, at the very least, to stop the higher frequency sound from reaching the woofer, and directing such higher frequency sound to the tweeter component which in turn is blocked from receiving all but the requisite high frequency audio delivery.
Such filter circuitry has generally comprised, as noted above, an inductor or inductance coil, a resistor, and a capacitor. In particular, the inductor coil generally requires several large turns or windings, e.g. on the order of about 50 to 250 such windings to provide adequate control or filtering of a coaxial speaker having two components and a basket of about 6.5 inches diameter. In other words, such an RLC filtering circuitry is quite expansive and bulky. Therefore, in previously-known speakers of the non-coaxial type, such RLC circuitry was either mounted within a large container for the speakers separate and apart from the actual speaker components and diaphragms thereof, or mounted remote from such units and provided with separate control lines leading to the speaker units.
In recent times, need for versatility in mounting of speaker components has increased. It has become desirable to mount such speaker components at specific locations in an automobile, along walls of a room, and notably upon ceiling panels or the ceiling within a room, to greatly enhance delivery of audio reception. In particular, conversion of pre-existing lighting fixtures to audio speakers has become of paramount interest in recent years, in order to enhance delivery of sound reception. There has been a great deal of interest in successfully mounting coaxial-type speakers upon a ceiling panel. However, it has not been previously possible to successfully mount such speakers and, at the same time, provide required audio reception, because it had not been possible to successfully mount a filtering network in conjunction therewith.
Since such RLC filtering network or circuitry is quite cumbersome and bulky, such circuitry would either have to be positioned upon a ceiling panel, greatly increasing the weight and the unwieldiness of the entire sound system, or such filtering circuitry would have to be mounted quite remote to the ceiling-mounted speaker, e.g. upon a wall of a room, and then coupled to the ceiling mounted speakers through separate lines or wires, also quite cumbersome and bulky, because, e.g., long connecting wires would be required between the filtering circuit and the speaker, resulting in increased potential failure of such circuitry.
Therefore, it had not been previously possible to feasibly mount a coaxial speaker with an adequate filtering system upon a ceiling panel, especially when such ceiling panel has been provided with a recessed baffle thereupon. If such speaker system was used without any RLC filter circuitry, then a tremendous amount of distortion resulted and sound quality emanating from the non-filtered speaker components was extremely poor or totally unacceptable.
However, it has now been found that it is possible to feasibly provide RLC filter circuitry in conjunction with a coaxial-type speaker, especially when such speaker is mounted upon a ceiling panel or a recessed ceiling baffle, securely and optimally providing the required filtering, while at the same time enhancing the overall structural positioning and arrangement of such a coaxial speaker system with maximum stability and reliability.